Welcome to the AC Tropical Fish aquarium forum. Our aquarium forum is the place to discuss any aquarium related issue in a friendly environment. Our aquarium forum welcomes aquarists of all levels from beginners to experts. Please ask a question in the how to section of our forum or read the FAQ section if you have any questions. register to and become a part of our friendly aquarium forum community today.

Specially designed sintered glass medium, with an enormous surface area of 18,300 sq. ft. per U.S. gallon.This highly-porous rock material promotes biological water purification and eliminates toxic ammonia and nitrite.

This is IMO the very best canister filter biomedia available on the market today. No other media offers the amount of surface area for bacteria to colonize then Ehfisubstrat. A little expensive, but it is the last biomedia you will ever buy for your canister or non-biowheel HOB filter.

I use this as a biofiltration media in literally all of my filters on all 14 tanks. Outstanding. You can find some good bargains on the media if you shop around and particularly if you are willing to purchase in bulk. Maintenance free, particularly if you have good upstream mechanical filtration available.